If you peruse sites like this, there’s a good chance you’ve come across the monitor discussion. “I’m buying a monitor, what size/resolution/refresh rate should I get?” Choosing the right monitor can be as important as (or, in some situations, even more important than) anything else in your build.

After all, your monitor is how you experience your build. The best graphics card and CPU don’t mean much if the monitor you’re using can’t show you the benefits of those parts.

PPI, Size, and Distance

The two big factors I see discussed are size and resolution (with G-Sync/Freesync, response time, and everything else considered somewhere down the line). After that’s decided, I usually see people opt for the largest and most expensive monitor they can afford. Most people don’t consider the pixels-per-inch (PPI) when looking at a monitor. You could get a 27-inch Acer Predator at 1440p resolution or a 24-inch Acer Predator at 1080p resolution and get very similar PPI.

The formula to calculate the PPI of a given monitor is this:

√((w²+h²))/diagonal

In that equation, w and h are the number of horizontal and vertical pixels and the diagonal is the size of the monitor. For instance, the 27-inch Acer Predator linked above is 2560 x 1440, so:

√((2560²+1440²))/27 = 2937.20956011/27 = 108.75 PPI.

Compare that to the 24-inch Predator that is 1920 x 1080—which is 91.79 PPI, a difference of just over 15%. Your eyes might notice that difference and they might not, but your wallet definitely will.

But why choose a smaller monitor if you can afford a larger one? The distance you sit from your monitor is a big factor as to what size your monitor should be. The further away you sit, the less the resolution matters. At 10 feet away, there’s a good chance that you won’t be able to tell the difference between 720p and 1440p—but you’ll want a projector like the LG Minibeam that can fill up a wall.

But you don’t need to get the biggest monitor possible! If your desk is shallow and you’re forced to sit close to your monitor, you can easily get away with a smaller monitor. Most people sit between 20 and 40 inches away from their monitors. There is no hard and fast rule for choosing the size of your monitor. Some people prefer to have a huge portion of their vision filled, others don’t. These are some things to keep in mind.

Another thing to mention is that the vision in your eyes is not symmetrical; you can only see 45 degrees inward towards your nose, but you can see 100 degrees outward towards your temple. That means that, if you want to keep your monitor within the vision of both eyes, you’ll need it to fit it inside the interior angle of both eyes.

Curved and Ultrawide Monitors

Some people use a curved monitor to get a bit more viewing area. The curved nature of the screen means that you’ll get more viewing surface in the same amount of horizontal width compared to a flat-screen monitor. They can be a good choice if you’re forced to sit close to your monitor. They can even provide a more immersive experience if you’re close enough. If your highest aim is pure immersion, however, then my opinion is that a VR headset like an HTC Vive or a Samsung Gear VR will provide the best experience.

Wide- and ultrawide-screen monitors are becoming more and more popular. Keep in mind that these are going to be harder to keep within your central vision. Not an issue if you are doing work and moving individual points of focus around the screen, but could in theory be an issue if you’re playing games and want to keep the entire screen in your view at all times.

You’ll also want to check on the aspect ratios allowed for the games you play. Many online games don’t allow more than 16:9 to keep everyone on a level playing field. And other games (even new triple-A, singleplayer-only titles) simply lack ultrawide support without justification. Also, I would be remiss if I didn’t acknowledge the existence of the 32:9 aspect ratio ultrawide by Samsung; at 49” it’s ridiculous and I love that it exists.

Conclusion

Keep in mind that there are trade-offs for a given resolution. If you opt for a 4K monitor, you’ll have a hard time going beyond 60 FPS without incredible hardware. Depending on how far you sit, you may not see much difference between 4K and 1440p. 1440p can get well beyond 100 FPS even on some modern midrange computers, but the response time is often worse than with a 1080p monitor. If you sit further away and opt for a larger monitor, you might enjoy a 1440p monitor at 120+ fps versus a 4K monitor at 60 FPS. You can also save a good chunk of money by going down in resolution.

Determining the best size for your needs should be the first step in choosing a monitor. You could do a bunch of math to try and figure out how much of your vision a monitor takes up at the distance you sit, but you’re better off determining it via testing—by going to a store and standing (at the same distance you would sit from a monitor at your desk) in front of a bunch of different sized monitors. After you figure out the size you want, you can optimize resolution, refresh rate, response time, and everything else for your budget.